The year 2006 marks my fiftieth year in the study and practice of radiology. The changes that have occurred in our specialty in the past half century are truly awe-inspiring. These advances, in many, many instances, have led directly to the immense progress that has been made in virtually all fields of medicine. What was it like to practice radiology 50 years ago and over the ensuing years? In these reflections I would like to relate my own personal journey during this time period, and use my particular interest in uroradiology and angiography as the focus of this review; in particular, the effect advances in these fields had on the diagnosis and treatment of renal masses. While I am focusing on renal cancer in this presentation, it is obvious that similar, and in some cases even greater, advances were made in the radiologic diagnosis and the subsequent effect on treatment of a wide array of diseases.
This journey should be of interest to younger radiologists working in the modern era of radiology who may not be aware of the earlier days in the specialty and can’t imagine what radiology was like one half century ago. I also suspect it will be of interest to “older” radiologists (they know who they are) who might reminisce with me as they recall their own experience in this journey.1 Sometimes, to appreciate the present and to contemplate the future, one has to look at the past.
In 1956 when I started my residency in radiology, the most effective way of diagnosing a renal mass was by nephrotomography, a technique that had just been described two years earlier (Evans, et al. 1954). Prior to nephrotomography, intravenous urography (often called intravenous pyelography or just IVP) was the least invasive way to evaluate the urinary tract and detect renal masses. Because urograms did not visualize the kidneys adequately in many cases, urologists frequently resorted to retrograde pyelography to diagnose a renal mass, since this technique provided superior demonstration of the collecting system structures. Urography and retrograde pyelography could detect a mass if it displaced the collecting system structures, or if it was large enough to create a density associated with the contour of the kidney, but it really couldn’t separate a cyst from a tumor unless the lesion contained calcification within it or it invaded the collecting system structures.
Renal mass puncture at that time was occasionally helpful but it was invasive and was successful only on very large lesions (FIGURE 1). Also, there was a high percentage of failed attempts because of difficulty in localization, and false positive and negative results were common. Often the decision to operate on a patient was based on the “clinical triad” of palpable mass, hematuria, and flank pain. “Exploratory surgery” was frequently performed for diagnosis and treatment. Benign cysts were often discovered and unroofed, or the kidney had to be removed if the diagnosis of cyst could not be established for certain at surgery. Nephrotomography therefore was a significant advance in the diagnosis of a renal mass at that time. Nephrotomography was essentially intravenous urography but with a much higher dose of intravenous contrast medium delivered (by hand) rapidly through a large-bore needle (12 gauge) and with tomograms taken during the nephrogram phase. This enabled a high level of contrast in the bloodstream, producing a dense nephrogram, and therefore superior visualization of the parenchyma of the kidney. Masses could then be seen as dense (tumor) (FIGURE 2) or lucent (cyst, if it had sharp margination and a thin wall) (FIGURE 3). The technique was made possible by the introduction at that time of contrast material that was significantly less toxic than what was previously available.2
Figure 1. Renal mass puncture: (A) Puncture with installation of contrast reveals a
large cyst. (B) Puncture with installation of contrast reveals a solid mass, representing a
renal carcinoma.
Figure 2. Renal cancer diagnosed by nephrotomography.
A large mass at the lower pole of the right kidney is “dense” and therefore
represents a solid vascular tumor.
Figure 3. Renal cyst diagnosed by nephrotomography. A “lucent” mass at the upper pole of the right kidney with an almost imperceptible
thin wall (arrow) is demonstrated.
Nephrotomography was actually a big advance over what had been available for renal mass diagnosis and it made differentiation of cyst and solid tumor very possible, particularly for larger lesions. The technique was quite successful in a number of medical centers but it suffered from false negatives (in hypovascular lesions), making clinicians often unwilling to accept the results. Also, the examination was often poorly performed by radiologists not used to inserting large-bore needles into veins, or reluctant to do a cutdown on an anticubital vein to enable the venous access necessary for rapid delivery of the large amount of contrast required to achieve the essential dense nephrogram. Because of this, poor studies were performed, and the technique never gained full acceptance by urologists, so that “exploratory surgery” was still commonly used, although somewhat less so than prior to the introduction of nephrotomography.
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